Messaging Only; Voice Quality Is Bad; Battery Life Is Bad; Connected Call But No Sound Or One Way Sound - ASCOM i75 Configuration Manual

Configuration Manual
Ascom i75 VoWiFi Handset

11.1.4 "Messaging only"

When the handset shows "Messaging only" it is configured to use both a gatekeeper and
an IMS/IP-WiFi, but has lost contact with the gatekeeper.
1 Check the Gateway address. Try to ping the gateway from another wireless client.
2 Try to send a message. The idle connection check interval to the IMS/IP-WiFi is much
longer than to the gateway. Sometimes when all network connection is lost the
handset will show "Messaging only" for quite some time, because it discovers it
has lost connection to the gateway much faster than it discovers loss of connection
to the IMS/IP-WiFi. In this case the i75 will eventually change to "No access".
3 If the phone is supposed to use Gatekeeper discovery, verify that the configured
Gatekeeper IP address is 0.0.0.0.
4 Check the Endpoint number and the Endpoint ID. If both are configured the MUST
match each other. Try clearing one of them.

11.1.5 Voice Quality is Bad

1 Check if QoS is working in both directions. Voice traffic should be prioritized on
both the LAN and the WLAN.
2 Connect to other phones (wired, analogue or external) to determine if it is the other
end that may cause bad quality.
3 Do a site survey and check for areas with under/over coverage and other interfering
802.11 systems.
4 Do a network performance test to ensure the wired LAN/backbone has adequate
capacity.
5 Use a spectrum analyser and look for non 802.11 interference.

11.1.6 Battery Life is Bad

1 Check "Beacon interval" and "DTIM" settings in the AP.
2 Verify the coverage, since low signal strength will make the handset to constantly
search for other APs and thereby consuming more power.
3 Use a sniffer and check the amount of broadcast traffic that is transmitted on the
WLAN.
4 Check if correct models of the chargers are used.
5 Verify with another battery.
6 If the system is supposed to use U-APSD for voice calls check the voice power save
mode parameter in the PDM.

11.1.7 Connected Call but No Sound or One Way Sound

1 Note the IP address of the handset. Turn the handset off and ping the IP address. If
something is found, the problem is an IP address conflict.
2 Check if the handsets are muted.
3 Use a headset to eliminate bad speakers/microphone.
2008-11-20/ Ver. B
TD 92431GB
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